The Japanese people and their government have reason to be nervous. Last year, North Korea conducted two ballistic missile tests over Japan. If that was not enough, the U.S. Government now appears to be contemplating what has been dubbed the “Bloody Nose Strategy”—a limited military strike against North Korean sites designed to drive home the message to the North Korean regime that it could pay a high price for its aggressive behavior.

In a recent post on Lawfare, Army Lt. Col. Shane Reeves and Army Capt. Rob Lawless have suggested that such a limited strike could be justified under international law. This elicited strong disagreement from Professor Kevin Jon Heller and, in a separate post, from Professors Mike Schmitt and Ryan Goodman. Meanwhile, retired Maj. Gen. Charlie Dunlap has weighed in on the debate to point out some further nuances.

We would like to pick up one strand of this discussion, namely the question of whether Article V of the 1960 Japan-U.S. Security Treaty could serve as a possible ground for the U.S. to use force against North Korea in the exercise of the right of collective self-defense without an express request by Japan or even without Japanese consent. Article V of the Japan-U.S. Security Treaty reads as follows:

Each Party recognizes that an armed attack against either Party in the territories under the administration of Japan would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional provisions and processes.

Any such armed attack and all measures taken as a result thereof shall be immediately reported to the Security Council of the United Nations in accordance with the provisions of Article 51 of the Charter. Such measures shall be terminated when the Security Council has taken the measures necessary to restore and maintain international peace and security.

A major concern that has traditionally troubled policymakers in Japan is whether the U.S. would be ready to take military action to defend Japan pursuant to Article V of the 1960 Treaty should the Japanese Government want it to do so. In recent times, this concern arose primarily in connection with the defense of the Senkaku/Diaoyu Islands. Last year, Defense Secretary James Mattis helped to allay these fears when he signaled a clear U.S. commitment to defend the islands in the event of an invasion by China. However, in an ironic twist, Japanese officials now might be feeling uneasy at the prospect that the U.S. could rely on Article V to take military action against North Korea against Japan’s wishes.

In the Nicaragua case, the International Court of Justice held that the exercise of the right of collective self-defense is conditional upon two requirements that apply on top of the conditions that govern the right of individual self-defense. First, there must be a request for assistance because customary international law does not permit, according to the Court, the exercise of collective self-defense “in the absence of a request by the State which regards itself as the victim of an armed attack” (para. 199). Second, the State for whose benefit the right of collective self-defense is exercised must declare itself to be the victim of an armed attack, as “there is no rule in customary international law permitting another State to exercise the right of collective self-defense on the basis of its own assessment of the situation” (para. 195).

To what extent does Article V of the Japan-U.S. Security Treaty alter this baseline position under customary international law? The provision makes two key points. First, each party recognizes that an armed attack against either party in territories under the administration of Japan would be dangerous to its own peace and safety. Second, each party declares that it would act to meet that common danger in accordance with its constitutional provisions and requirements.

Although Article V of the Japan-U.S. Security Treaty does not stipulate that an armed attack on one party shall be considered an armed attack on the other, as does the North Atlantic Treaty, the legal dynamics are similar. The second part of Article V foresees that one party, say the U.S., which has not suffered an armed attack, may take action that must be reported to the Security Council under Article 51 of the UN Charter. The only reason why such a reporting obligation would arise in these circumstances is because the U.S. uses force in the exercise of the right of collective self-defense. It is not unreasonable, therefore, to read the shared recognition that an armed attack against Japan is dangerous to the peace and safety of the U.S., and the Japanese acceptance that the U.S. would use force in such circumstances in the exercise of the right of collective self-defense, as a standing request for U.S. military assistance should Japan become the victim of an armed attack.

If this interpretation is correct, an armed attack on Japan would not only impose an obligation on the U.S. to adopt appropriate measures, but it would also confer upon it a right to take forcible action without the need for a specific Japanese request to this effect, even where Japan is prevented from taking action in its individual self-defense for domestic legal or political reasons.

This interpretation is supported by an exchange of notes (available in Japanese) between the Japanese and U.S. governments in 1966 regarding the implementation of Article VI of the Japan-U.S. Security Treaty, which deals with the use of facilities and areas by U.S. forces in Japan. The exchange of notes confirms the Japanese government’s position that any significant adjustment to the deployment and equipment of U.S. forces stationed in Japan, and their use of facilities and areas in Japan for the purpose of conducting combat operations overseas, is subject to prior consultation with the Japanese government. Significantly, this note expressly excludes Article V operations from the scope of this prior consultation requirement.

This deliberate exclusion of collective self-defense from the consultation requirement suggests that Japan has accepted that the U.S. is free to take military action in the event that Article V is triggered without consulting the Japanese government and therefore, logically, without a specific Japanese request for assistance or prior Japanese consent.

Should this interpretation be correct, it could have far-reaching consequences if the Japanese and U.S. governments were to take different views regarding the legality or strategic wisdom of taking military action against North Korea pursuant to Article V of the 1960 Treaty. In such circumstances, could Japan withdraw its standing request for assistance?

Doctrinal considerations militate against this. If Article V truly reflects an agreement between the two parties on a standing request for assistance in the event that Japan should suffer an armed attack, it would be incompatible with the obligatory nature of such an agreement if Japan were able to unilaterally revoke it (see Judge Sir Hersch Lauterpacht’s separate opinion in Norwegian Loans). Japan either agreed to a standing request or it did not. If it did, the procedure for revoking it is to be found in Article X of the 1960 Treaty, which permits Japan to give notice of its intention to terminate the Treaty, whereupon the Treaty would terminate one year after such notice has been given.

However, such an eventuality would be catastrophic to the stability of the Asia-Pacific, given the pivotal role the Japanese-U.S. alliance has played for the maintenance of peace and security in the region. A more compelling avenue is to argue that reliance by the U.S. on the right to use force in the collective self-defense of Japan under Article V of the Treaty against the express wishes of the Japanese government would be contrary to the object and purpose of the Treaty, which is to facilitate mutual cooperation in dealing with the common dangers affecting the peace and safety of the two nations. Putting aside the legal questions, we should not lose sight of the broader strategic and political context: There are good policy reasons why the U.S. should act in concert with, rather than in opposition to, Japan.

 

Image: U.S. Department of Defense